/* 顶部通栏 */
.top-bar {
  background-color: #165dff;
  color: #fff;
  padding: 8px 120px;
}
.school-nav {
  display: flex;
  align-items: center;
  gap: 20px;
}
.school-nav img {
  height: 32px;
}
.school-nav a {
  color: #fff;
}

/* 主导航栏 */
.main-nav {
  background-color: #fff;
  box-shadow: 0 2px 8px rgba(0,0,0,0.08); /* 轻微阴影，提升层次感 */
  padding: 0 120px;
}
.main-nav ul {
  display: flex;
  list-style: none;
}
.main-nav li {
  position: relative;
  padding: 16px 24px;
}
/* 下拉菜单 */
.dropdown-menu {
  position: absolute;
  top: 100%;
  left: 0;
  background-color: #fff;
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
  width: 200px;
  display: none; /* 默认隐藏 */
}
.dropdown:hover .dropdown-menu {
  display: block; /* hover时显示 */
}
.dropdown-menu li {
  padding: 12px 16px;
}